Vascular System Notes

Tunica Intima and Media

  • Media (mamma):

    • Contracts and dilates to control vessel size.

  • Intima:

    • Adventurous, located on the outside.

Capillaries

  • Essential for exchange of substances.

Veins

  • Contain 75% of the body's total blood volume.
  • Possess valves to prevent backflow.
  • Valves appear as mounds between vein stretches.
  • Avoid starting IVs too close to valves.
  • Vein selection should consider valve locations.
  • Valves are typically found at joints where veins merge.

Leg Veins and Valves

  • Prevent backflow of blood.

  • Important for nurses to understand in the context of edema.

  • Interventions for patients with swelling:

    • Compression socks: reduce swelling.
    • Walking: Contractions from walking squeeze valves, promoting blood flow.
    • Compression devices: Mimic muscle contractions to aid blood flow.
    • Passive and active range of motion.

Lotion Application

  • Important for massage, promoting circulation.
  • Apply lotion upwards, towards the body, to aid circulation.

Lymphatic Vessels

  • Collect lymphatic fluid from tissues.
  • Empty into the circulatory system via the subclavian and internal jugular veins.
  • Essential for moving fluid out of interstitial spaces.

Vasodilation and Vasoconstriction

  • Dependent on the body's metabolic needs.

  • Vasoconstriction:

    • Occurs when blood pressure needs to increase.

  • Vasodilation:

    • Occurs when blood pressure needs to decrease.

  • Injury Response:

    • Heat: Vasodilates to increase blood flow to the injured area.
    • Cold (Ice): Vasoconstricts to prevent swelling immediately after an injury, commonly used in sports injuries.

Vasoconstriction and Vasodilation Ability

  • Essential for the body to respond to medications and manage blood flow.

Bruits

  • Caused by turbulent blood flow.

  • Auscultation locations:

    • Aorta: Normally, no bruit should be heard.

  • Presence of a bruit indicates turbulent flow and may suggest an aneurysm.

Aneurysm

  • Involves the weakening of vessel walls.

Intermittent Claudication

  • Definition:

    • Cramps in lower legs during exercise or activity that are relieved by rest.

  • Indicates peripheral arterial insufficiency.

  • Insufficient oxygen-rich blood supply to the legs.

  • Leads to lactic acid production and hypoxia.

  • Intermittent nature: Comes and goes.

  • Clinical manifestation of vascular disorders.

  • Tissues complete energy cycle without adequate nutrients and oxygen, leading to lactic acid production.

Arterial Disorders

  • Decreased blood flow:

    • Produces cool and pale extremities.
    • Leg elevation: Causes whiteness due to decreased blood flow working against gravity.
    • Leg Dependency: Can result in rubor (redness) due to blood pooling.

  • Rubor:

    • Redness observed within 20 seconds to 2 minutes after placing the extremity in a dependent position.

  • Priority Assessment:

    • Pulses.
    • Capillary refill.

  • Pulse Assessment:

    • If pedal pulse is not palpable, move up or use a Doppler.

  • Documentation:

    • Unable to palpate pedal pulse, pulse verified with use of doppler, and the rate.

Diagnostic Tests for Vascular Disorders

  • Ankle brachial index.
  • Exercise testing.
  • CT angiography.

Arteriosclerosis and Atherosclerosis

  • Often used interchangeably but are not the same.

  • Arteriosclerosis:

    • Hardening of the vessels.

  • Atherosclerosis:

    • Affects the intima of large and medium-sized arteries.
    • Accumulation of lipids, calcium, blood components, carbohydrates, and fibrous tissue, forming plaque.
    • Plaque can occlude blood flow and break off, forming emboli.

Coronary Arteries

  • 75% obstruction of one or more coronary arteries can cause sudden cardiac death.
  • Located on the outside of the heart, like a crown.
  • Must be open to ensure the heart receives oxygen.

Atherosclerosis Pathophysiology

  • Plaque formation encourages platelet aggregation, worsening blockage.

Atherosclerotic Lesions

  • Fatty streaks: Yellow and smooth.
  • Fibrous plaques: Composed of smooth muscle cells and collagen fibers, can become progressive.

Collateral Circulation

  • Body attempts to reroute blood flow around occlusions by creating additional smaller vessels.
  • Not as effective as original arteries but helps the body cope until a cardiac event occurs.

Risk Factors for Atherosclerosis

  • Modifiable:

    • Smoking.
    • Diet.
    • Hypertension.
    • Diabetes (Type 2).
    • Stress.
    • Sedentary lifestyle.

  • Non-Modifiable:

    • Increased age.
    • Gender.
    • Genetics.

Management of Atherosclerosis

  • Vasodilation.

  • Preventing vascular compression.

  • Surgical Management: Angioplasty.

  • Angioplasty:

    • Vessel reconstruction (angio = vessels, plasty = reconstruction).

  • Statins:

    • Cholesterol medications that reduce fatty deposits. Usually end with "-statin".
    • Taken at night for better control.

Arterial Insufficiency

  • Legs are most often affected.

  • Lesions can extend from the aorta to below the renal artery.

  • Peripheral Arterial Disease (PAD) symptoms:

    • Intermittent claudication.
    • Decreased ability to walk.
    • Ischemic pain at night.

  • Assessment:

    • Cold extremities.
    • Numbness.
    • Skin changes, hair distribution.

  • Treatment:

    • Balloon angioplasty: Compresses plaque against artery walls to increase space.
    • Risk of emboli.

Raynaud's Phenomenon

  • Intermittent arterial or vasal constriction.
  • Symptoms: White, red, and blue color changes, numbness, tingling, and burning pain in hands.
  • Triggered by cold sensitivity or vasoconstriction (e.g., smoking).
  • More common in women before age 30.
  • Nursing Management: Education to protect hands, avoid cold exposure, and stop smoking.

Venous Insufficiency

  • Problems with valves in the legs.

  • Obstruction or reflux in venous valves.

  • Goal: Keep blood flowing towards the heart.

  • Clinical Manifestations:

    • Edema.
    • Altered pigmentation.
    • Pain.
    • Stasis dermatitis.
    • Dilated superficial veins.
    • Dry, cracked, itchy skin.
    • Cellulitis.

Leg Ulcers

  • Arterial and venous ulcers have distinct features.

  • Arterial Ulcers:

    • Symptoms: Intermittent claudication.
    • No edema.
    • No pulse or weak pulse.
    • No drainage.
    • Round, smooth edges.
    • May have eschar (scab).

  • Venous Ulcers:

    • Pulse is present.
    • Irregular sores with irregular borders.

Varicose Veins

  • Abnormally dilated superficial veins caused by incompetent venous valves.
  • More common in occupations requiring prolonged standing.
  • Can be hereditary.

Diagnostic Tests and Post-Procedure Care

  • Informed consent.
  • Check insertion site.
  • Use sandbags to apply pressure and monitor for bleeding.
  • Patient must lay flat for a specified time (e.g., 4-6 hours).